Rotary vane compressors are used in a variety of applications. One such compressor includes a rotor having vane receiving slots with a vane in each slot. The rotor is rotated, in an eccentric manner, in a cavity within a body to produce compressed gas. One major application is in home sewage treatment. There the rotary vane compressor is used to pump air into home sewage treatment tanks to provide bacteria growth, which in turn, will break down the effluent in the tank. The compressor is typically located outside, next to the house and operates continuously.
A typical rotary vane compressor is sold by Gast Manufacturing, Inc. of Benton Harbor, Mich., 49023-0097 as its “23 Series”. These compressors usually include the following components: (1) a motor in a vented housing having a bearing mounted drive shaft; (2) a vented back plate or closure for the motor housing; (3) a rear plate mounted to the housing and though which the shaft extends; (4) an inlet ring between the motor housing and rear plate; (5) a rotor with vanes mounted to the drive shaft, and positioned within a body; (6) a vented shroud surrounding the body which abuts the motor housing; (6) a front plate that bears against the body and rotor; and (7) a muffler box positioned against the front plate and through which air enters and exits the compressor.
The muffler box, front plate, body, rear plate and motor housing are secured together. The major moving parts are the motor, drive shaft, bearings and rotor with vanes all of which produce sound. However, vibration of the non-moving parts is also important. The compressor emits sound during operation, which due to its 24-hour operation can become irritating over time.
It is an object of this invention to reduce the sound of the compressor when it operates.
This and other objects of the invention will become apparent from the following description and independent claims.